Area Forecast Discussion
Issued by NWS Twin Cities, MN

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41
FXUS63 KMPX 092328

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
628 PM CDT Wed Aug 9 2017

.SHORT TERM...(This evening through Thursday)
Issued at 425 PM CDT Wed Aug 9 2017

Showers from this morning have primarily moved east of I-35 & will
continue to drift into Wisconsin as the evening progresses. The
next round of precipitation is already developing, primarily along
a cold front across the eastern Dakotas. This activity will
become more widespread & spread further east this evening as the
cold front approaches. A few isolated cells have developed across
far western MN ahead of the front & where skies have cleared since
this morning. 1000-1500 J/Kg of MLCAPE has already developed
across western MN where the strongest thunderstorm activity is
expected. Effective-layer bulk shear in this region is only on the
order of 20-30 kts so widespread organized convection is not
expected, but a few of the strongest clusters may be able to
produce a few instances of small hail & gusty winds. Only
expecting a few hundred J/Kg of CAPE to persist into central &
eastern MN so expect activity this evening to be mostly showery,
with a few rumbles of thunder.

Showers & thunderstorms tonight should move out of the area before
sunrise, with some localized patchy fog possible in areas that
receive the most rainfall tonight. A cool & cloudy day is expected
tomorrow behind the cold front with temperatures on the order of
10 degrees below normal. Steepening mid-level lapse rates behind
the front should result in just enough instability to kick off
some widely scattered showers/thunderstorms tomorrow afternoon.
Best chances for this precipitation will be along & east of I-94.

.LONG TERM...(Thursday night through Wednesday)
Issued at 425 PM CDT Wed Aug 9 2017

Very quiet long term period, with limited precip chances and
continued cooler than normal weather. Do not anticipate severe
weather in the long term period.

By tomorrow night, the shortwave trough will be off to our east
moving through the Great Lakes.  Wrap-around showers will be coming
to an end across western MN by that time.  High pressure will build
in behind this activity and setup Friday to be a very nice day.  The
dry weather looks to continue into Saturday, but could see some
showers and isolated thunderstorms develop Saturday afternoon as
another upper level shortwave moves in from our west. The forcing
with this feature looks to primarily move across southwest
Minnesota into Iowa, with the best chance of precip coming on
Sunday morning across far southern Minnesota. This looks to be our
only real shot at measurable rain through the long term period.

The longwave trough will remain in place and continue to provide
northwesterly flow aloft and temperatures will continue to be below
normal.  And with the remainder of the forecast relatively dry,
there aren`t any hazards to be concerned with early next week.


.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 625 PM CDT Wed Aug 9 2017

Regional radar/satellite imagery indicated that convection was
developing along a frontal boundary in far eastern South Dakota,
and extended north into North Dakota. A few showers, storms are
possible in far southern Minnesota until 1-2z, but the better
forcing/instability comes in later along the front. Therefore,
will continue the VCTS during the evening for all of Minnesota TAF
sites, with KAXN having a tempo period as this site will likely
see the bulk of the heavier SHRA before 3z. Otherwise, the front
will move across the region, with MVFR/IFR cigs developing behind
it later tonight. Cigs will begin to lift during the typical
mid/late morning, but still holding in the MVFR range. A few
SHRA/VCTS are still possible Thursday afternoon, but coverage
remains low for any VCTS at this time.


MVFR cigs around the airport is the main concern for the next
couple of hours. Otherwise, VCTS/SHRA that are developing near the
Minnesota/South Dakota border will spread eastward and begin to
affect eastern Minnesota between 3-5z. MVFR cigs will likely
develop in the wake of the frontal passage and continue thru the
mid/late morning hours.


Fri...VFR. Wind N 5-10 kts.
Sat...VFR. Wind NE 5 kts.
Sun...VFR. Slight Chc SHRA/TSRA afternoon. Wind ESE 5 kts.




AVIATION...JLT is the U.S. government's official web portal to all federal, state and local government web resources and services.